RFR: 8335392: C2 MergeStores: enhanced pointer parsing [v5]

[Emanuel Peter]

On Mon, 21 Oct 2024 21:01:15 GMT, Dean Long <dlong at openjdk.org> wrote:

>> Emanuel Peter has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   rm dead assert
>
> src/hotspot/share/opto/noOverflowInt.hpp line 66:
> 
>> 64:     if (a.is_NaN()) { return make_NaN(); }
>> 65:     if (b.is_NaN()) { return make_NaN(); }
>> 66:     return NoOverflowInt(java_subtract((jlong)a.value(), (jlong)b.value()));
> 
> For add and subtract, I don't think two 32-bit inputs can cause a 64-bit result to wrap or overflow, but it could then using the java_ APIs that wrap would hide the overflow.  I think you can safely use + and - for these two.

Ok, I'll change it to `jlong +/-`

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PR Review Comment: https://git.openjdk.org/jdk/pull/19970#discussion_r1810061123